Influence of distributed reduced graphene oxide clusters on methanol sensing performance of TiO2 nanotube based device

Abstract

Present paper aims to improve the methanol sensing performance of TiO2NT based devices by incorporating to RGO clusters on top of the TiO2NT matrix in a distributed format. The binary hybrid structure of RGO/TiO2 was found to offer dramatic improvement in terms of response magnitude (34% at 700 ppm), response time (24 s) and recovery time (116 s) compared to its bare TiO2 counterpart. The possible cause for such improvement may be due to availability of additional adsorption sites on RGO layer and high electron mobility of the same. Thus, future developments may rely on a synergistic hybridization approach of these two categories of materials as sensing elements. In the present endeavour, a systematic comparison of the bare TiO2 nanotube based sensor and reduced graphene oxide-TiO2 based sensor was carried out with methanol vapor as the test species. The later was found to offer remarkably superior performance concerning the sensor parameters like response magnitude, response time and recovery time.